KVM: x86: Add a VALID_MASK for the flags in kvm_msr_filter_range

Add the mask KVM_MSR_FILTER_RANGE_VALID_MASK for the flags in the
struct kvm_msr_filter_range.  This simplifies checks that validate
these flags, and makes it easier to introduce new flags in the future.

No functional change intended.

Signed-off-by: Aaron Lewis <aaronlewis@google.com>
Message-Id: <20220921151525.904162-5-aaronlewis@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/include/uapi/asm/kvm.h b/arch/x86/include/uapi/asm/kvm.h
index ae43246..c6df6b1 100644 (file)
--- a/arch/x86/include/uapi/asm/kvm.h
+++ b/arch/x86/include/uapi/asm/kvm.h
@@ -214,6 +214,8 @@ struct kvm_msr_list {
 struct kvm_msr_filter_range {
 #define KVM_MSR_FILTER_READ  (1 << 0)
 #define KVM_MSR_FILTER_WRITE (1 << 1)
+#define KVM_MSR_FILTER_RANGE_VALID_MASK (KVM_MSR_FILTER_READ | \
+                                        KVM_MSR_FILTER_WRITE)
        __u32 flags;
        __u32 nmsrs; /* number of msrs in bitmap */
        __u32 base;  /* MSR index the bitmap starts at */

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5208b95..e46e458 100644 (file)
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6407,7 +6407,7 @@ static int kvm_add_msr_filter(struct kvm_x86_msr_filter *msr_filter,
        if (!user_range->nmsrs)
                return 0;
 
-       if (user_range->flags & ~(KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE))
+       if (user_range->flags & ~KVM_MSR_FILTER_RANGE_VALID_MASK)
                return -EINVAL;
 
        if (!user_range->flags)